Safety cranking device.



L BUSH.

SAFETY cmmma DEVICE.

APPLICATION FlLED JULY 24, 1916.

Patented Jul 10, 1917.

2 SHEETSSHEET 1.

.l. J. BUSH.

SAFETY CRANKING DEVICE.

APPLICATION man .IULY24, ms.

1,232,892. @Patented July 10, 1917.

2 SHEETS-SHEET 2.

in the engine crank of structural change, therem.

the front ;-spring 3 9 .J'AMES J. BUSH, TACOMA, WASHINGTON.

- SAFETY CRAN'KING DEVICE.

Specification of Letters Patent.

Patented July 10, 1917.

' Application filed J'u1y24, 1916. Serial No. 111,046.

- To all whom it may concern:

Be it known that I, JAMES J. BUSH, a citizen .of the United States, residing at Tacoma, in the county of Pierce and State of Washington, have invented certain new and useful Improvements in Safety Cranking'Devices, of which the following is a specification.

This invention contemplates an improved safety cranking device for explosive enines, being particularly designed for use in Connection with motor vehicles.

The invention has as its primary object to provide a deviceof this character wherevvill be automatically freed upon the retrograde movement of the engine shaft or back-firing of the engine.

The invention has as a further object to provide a constructlon wherein the engine "crank back-firing of the engine so that by no possibility canthe operator be injured by a retrograde movement of the crank.

a still further object of the invention is to provide a device of this character which ma be and used in connection with motor vehicles of conventional type without the necessity Other and incidental objects will appear as the description proceeds and in the drawings wherein I have illustrated the preferred embodiment of the invention and wherein si ilar reference characters desig nate corresponding parts throughout the several views:

Figure lis a perspective view showing my improved device'applied to the spring yoke of a conventional type of vehicle,

Fig. 2 1s a plan view partly in section more particularly showing the mounting of the device,

Fig. 3 is a longitudinal sectional view more particularly illustrating the arrangement of the spring employed for holding the device in inactive position away from theengine shaft, and

Fig. dis a plan view of a slightly modified form of the invention.

In order to more clearly illustrate the construction, mounting, and operation of my improved device, I have in the drawings, illustrated the invention in connectlon with he 10 of a conventional t e of motor vehicle. Mounted upon the said yoke is a suitable casting 11 which reextremities,

will be completely detached upon readily mounted in position ceives U-bolts 12 connecting the said casting with the front spring of'the vehicle. The casting 11 is formed to receive the forward terminal of theiengine pan 13 which is provided with a head 14 journaled upon the said casting and retained in position by. a clip 15. The engine shaft is shown at 16 and, as is usual, the adjacent terminal thereof is provided with a pin 17. i

Coming now more articularly to the subject of the present invention,

terminal of the head 1 1 and provided, at its with forwardly directed cars 19 adapted to whereby the said plate is connected to the casting 11 and to the vehicle. J ournaled win the plate 18 is a crank shaft 20 carrying, at its inner extremity, a

clutch head or collar 21 forind to receive the adjacent terminal of the engine shaft 16 and provided with an annular series of teeth for engagement with the pin 17. The clutch head 21 is connected with the shaft 20 by a suitable pin 22 extending through the said shaft and interposed between the said head and the plate 18 to surround the shaft 20, isa sleeve 23. At its outer ex tremity, the shaft 20 is formed with a longi:

tudinally tapered terminal 24: and mounted upon the said shaftis a crank 25 which is provided with a head 26 receiving the said terminal. Detachably connecting the crank :with the shaft is a frangible pin 27 extending through the shaft.

Formed on the plate 19 to extend forwardly therefrom is an annular series of clutch teeth 28 arranged to surround the shaft 20 in spaced'relation thereto and interposed between the said plate and the head 26' of the crank is a clutch sleeve or collar 29. This collar is slidably mounted upon the shaft 20 and at its inner extremity, is

formed with an annular series of clutch teeth 30 surrounding the shaft 20 in spaced relation thereto and arranged to cooperate with the teeth 28. At its outer extremity, the sleeve 29 is formedfwith an annular series of ratchet teeth 31 arranged to coope erate with a similar series'of ratchet teeth 32 fcrmed' on the head 26 of the crank 25. Interposed between the plate 18 and the sleeve 29 is a helical spring 33. This spring is arranged to surround the shaft 20 and is received, at its inner-end, by a boss34 upon the plate 18 and at its outer end by a s1mi- I employ a body plate 18 formed to fit against the outer receive. the adjacent terminals ofthe U-bolts 12 lar boss upon the sleeve 29 with the said bosses supporting the spring in spaced relation to the said shaft. Mounted upon the forward side of the plate 18 to surround the ratchet teeth 28 and 30 'is a stop casing 36. This casing, at its inner extremity, is provided with laterally directed ears 37 seating against the plate 18 and receiving bolts or other suitable fastening devices 38 connecting the casing to the said plate. At its outer end, the casing 36 is formed with an inwardly directed annular stop flange 39 engageable with a shoulder 40 upon the sleeve 29 for limiting the said sleeve in its outward movement under the tension of the spring 33. In this connection, it will be observed that the casing 36 fits snugly about the clutch teeth 28 while the clutch teeth 30 are freely received within the said casing so that the sleeve 29 may readily slide longi;

tudinally within the casing.

normally urge the sleeve 29 outwardly upon the shaft20 to hold the ratchet teeth 31 of the said sleeve in engagement with the ratchet teeth 32 of the crank 25 with the said sleeve b e'ariiigag'ainst the said crank to normally shift and hold the clutch head 21 away from the pin 17 of the engine shaft 16. To crank the engine, the crank 23 is grasped c and inward pressure exerted thereon to shift the shaft 20 inwardly against the tension of the spring 33 to engage the clutch head 21 with the pin 17 when the clutch teeth 30 of the sleeve 29 will, as more particularly shown in Fig. 2 of the drawings, be moved to engage with the clutch teeth 28 of the plate 18. The crank 25 may then be turned to rotate the shaft 20 and consequently rotate the shaft 16 to crank the engine, the ratchet teeth 32 of the crank, riding as the crank is turned, over the ratchet teeth 31 of the sleeve 29. Should the engine back-fire during this cranking operation to cause a retrograde movement of the engine shaft 16, reverse rotation of the engine shaft will be communicated to the shaft 20 through the clutch head 21. Retrograde movement of the shaft 20 will cause the ratchet teeth 32 of the crank 25 to engage with the ratchet teeth 31" of the clutch sleeve 29. The ratchet teeth 30 of the said sleeve will then cooperate with the ratchet teeth 28 of the plate 18 to hold the said sleeve fixed with respect to the shaft 20 and consequently hold the'crank 25 fixed with respect to the said shaft. The retrograde movement of the engine shaft will, therefore, not to shear the connecting pin 27 of the crank and entirely free the crank from the shaft 20 and; since the shaft 20 is formed with the tapered terminal 24:, the said shaft will readily release the crank so that by no possibility can back firing of the engi ne injure the operator..

As will be readily understood, the crank-may shaft 20 by a rigid pin 41 while the clutch head 21 is detachably connected with the shaft by a frangible pin 42. As will'b'e seen, in view of the preceding description, the pin 42 will be automatically broken or sheared ofi upon retrograde movement of the engine shaft 16 to disconnect the clutch head 21 from the shaft 20 so that the reverse"rotation of the engine shaft will not be communicated to the crank 25. In this As will now be clear, the spring 33 will' modification, the stop casing 36 is eliminated since, uponireeing of the cutch head 21, the sp ring3 3 cannot, under normal circumstan'ces, act to displace the shaft 20. Otherwise, the construction of this modification is identical withthat of the preferred form of the invention and a further description of such modified structure is accordingly deemed unnecessary.

Ilaving thus described my invention,what I claim and desire to secure by Letters Patent is: I

1. A safety cranking device for explosive engines including a cranking shaft, a crank carried thereby, a frangible element associated with the said shaft, and means for automatically breaking the said element upon retrograde movement of the engine crank shaft to interrupt the motion thereof with respect to the said crank, said means including a body'member fixed with respect to the cranking haft, a sleeve mounted upon said cranking s aft and disposed to operatively engage the body member to be held fixed with'respect thereto, means coiiperating with the said sleeve and normally urging the sleeve outwardly to operatively engage the crank and means for limiting the sleeve in its outward movement.

2. A safety cranking device for explosive engines including a cranking shaft, a crank carried thereby, a frangible element associated with the said shaft, and means for automatically breaking the said element upon retrograde movement of the engine crank shaft to interrupt the motion thereof with respect to the said crank, said means including a body member fixed with respect to the cranking shaft, a sleeve disposed to engage with the body member to be held fixed with respect thereto, yieldable means i normally urging said sleeve outwardly to operatively engage the crank, and

a mp7 casing surrounding the sleeve'fornengagement therewith to limit the sleeve in its outward movement.

3. A safety cranking device for explosive engines including a cranking shaft, a crank carried thereby, a frangible element associated with the said shaft, and means for automatically breaking the said element upon retrograde movement'of the engine crank shaft to interrupt the motion thereof with respectto the said crank, said means including a body plate fixed with respect to the cranking shaft, clutch teeth carried by the said plate, a sleeve carried by the cranking shaft, clutchv teeth carried by the said sleeve and disposed to engage the clutch teeth of the plate for holding the sleeve fixed with respect to the plate, ratchet teeth carried'by the crank, ratchet teeth carried by the-sleeve and disposed to engage the teeth of the crank, a spring bearing between said plate and sleeve for normally urging the sleeve outwardly to cooperate with the crank, anda casing surrounding the clutch teeth of the plate and sleeve and provided with a shoulder for engagement with the saidsleeve to limit the sleeve in its out-.

ward movement.

4. A safety cranking device for explosive enginesincluding a cranking shaft, a crank to the said crank, said means including a body member provided with ratchet teeth, ratchet teeth formed on the inner terminal of the crank, and a sleeve having ratchet teeth at its inner extremity for engagement with the ratchet teeth of the body member for holding the sleeve fixed with respect to the said member andprovided with ratchet teeth at its outer extremity to cooperate with the ratchet teeth of the crank, the 00- operating ratchet teeth of the crank and sleeve being of less length than the cooperating teeth of the sleeve and body member with the teeth of the crank disposed to normally ride over the coacting teeth of the sleeve.

5. A safety cranking device for explosive engines including a cranking shaft, a crank mounted upon the outer extremity of said shaft, a frangible connection between the crank and the shaft, and means for automatically breaking the said connection upon retrograde movement of the en e crank,

the said means including a ho y member fixed with respect to the cranking shaft, a

sleeve disposed to operatively engage the body member to be held fixed with respect to the crank, and means urging the sleeve outwardly to operatively engage the crank with the said means disposed to act upon the sleeve to displace the crank from the said cranking shaft upon the breaking of the said connection.

In testimony whereof I afiix my signature.

.- JAMES J. BUSH. 

